title: Yeasts and lactic acid bacteria mixed-specie biofilm formation is a promising cell immobilization technology for ethanol fermentation.
abstract: We previously found that some Saccharomyces cerevisiae and Lactobacillus plantarum remarkably formed mixed-specie biofilm in a static co-culture and deduced that this biofilm had potential as immobilized cells. We investigated the application of mixed-specie biofilm formed by S. cerevisiae BY4741 and L. plantarum HM23 for ethanol fermentation in repeated batch cultures. This mixed-specie biofilm was far abundantly formed and far resistant to washing compared with S. cerevisiae single biofilm. Adopting mixed-specie biofilm formed on cellulose beads as immobilized cells, we could produce enough ethanol from 10 or 20 % glucose during ten times repeated batch cultures for a duration of 10 days. Cell numbers of S. cerevisiae and L. plantarum during this period were stable. In mixed-specie biofilm system, though ethanol production was slightly lower compared to S. cerevisiae single-culture system due to by-production of lactate, pH was stably maintained under pH 4 without artificial control suggesting high resistance to contamination. Inoculated model contaminants, Escherichia coli and Bacillus subtilis, were excluded from the system in a short time. From the above results, it was indicated that the mixed-specie biofilm of S. cerevisiae and L. plantarum was a promising immobilized cell for ethanol fermentation for its ethanol productivity and robustness due to high resistance to contamination.
authors.affiliation: Department of Food Bioscience and Biotechnology, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-8510, Japan.
authors.forename: Atsumu
authors.initials: A
authors.lastname: Abe
authors.forename: Soichi
authors.initials: S
authors.lastname: Furukawa
authors.forename: Shinya
authors.initials: S
authors.lastname: Watanabe
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Morinaga
mesh_terms: D061249:Batch Cell Culture Techniques / Q000379:methods*; D018441:Biofilms / Q000254:growth & development*; D018914:Cells, Immobilized / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D019344:Lactic Acid / Q000096:biosynthesis*; D048191:Lactiplantibacillus plantarum / Q000166:cytology / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology
chemical_list: D019344:Lactic Acid; D000431:Ethanol